>>27945402>>27945161>>27945061According to what little Information from the pokedex that actually makes sense AND the stuff skimmed from their abilities and move sets from both Hariyama and Maukuhita:
Hariyama ARE actually fat; Hariyama have a thick layer of heat and cold absorbing fat that they spend their adolescent period as a Makuhita building up in order to survive the mountainous regions they dwell within, to power and fuel the development of their muscles as well as to keep themselves from ripping their own bodies apart from being just one huge ball of muscles.
Makuhita spend their days building muscle and EATING; they most likely live a lot like bears eating anything they can get their weird mittens on so they can build fat and muscle: nuts, fruit, berries, eggs, probably even going so far to hunt steel, rock, normal type Pokemon they have a type advantage or catching fish-water pokemon.
Their ability "guts" might also lend or suggest evidence to this kind of thinking: being guts would come in handy when your prey tries to poison, sleep or paralyze you- work through that status ailment so you can fuckin' eat em'.
So in short: Yes, they're both fatties, but they're functional fatties.